The aim of this study was to explore the characteristics of a non-gelling exopolysaccharide (EPS) obtained from Lactobacillus delbrueckii subsp. bulgaricus NCFB 2483 and a gelling EPS obtained from Sphingomonas elodea ATCC 31461 (31461). The EPSs were isolated from the two bacterial strains grown in milk permeate-based media. They were purified and then characterised using light scattering and viscometric techniques. A greater emphasis of this research was placed on 2483 EPS since its physical characteristics have not been reported to date. In the case of 31461 EPS. a model for gelation of the sodium gellan was proposed based on rheological and light scattering measurements. The rheological properties of the two EPSs were also compared with several commercial polysaccharides. Microscopy examination of 2483 EPS was carried out using confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). In CLSM, the lectin SBA (from Glycine max) Alexa Fluor 488 conjugate was used to stain the EPS since it has affinity for galactopyranosyl residues present in 2483 EPS. The CLSM micrographs showed a random distribution of EPS aggregates in the culture medium. At high magnification, the SEM micrographs showed web-like EPS structures. These structures were formed during the critical point drying process, when the EPS, which filled the interstices and channels of the protein aggregates, dehydrated. The 2483 EPS aggregates were found to be stable at neutral or low pH (~3.9) but were disrupted at high pH (pH 8-10). Procedures commonly used to quantify EPS from culture medium were found to be unreliable. In the development of an improved EPS assay, each of the processing steps was examined. Key improvements included the use of Flavourzyme for protein hydrolysis; optimising ethanol concentration to prevent lactose crystallisation yet allowing complete EPS precipitation; and a suitable centrifugation regime to minimise EPS loss. The improved EPS assay gave reproducible results (5% coefficient of variation). The isolation of 2483 EPS from milk media proved to be a difficult task because of interference from non-EPS components. An effective and simple approach allowing maximum EPS recovery involved the use of a hydrolysed milk medium which was ultrafiltered (UF) to remove molecular species larger than 2.5 x 105 Da. The UF permeate was suitable for the growth of 2483 with an EPS yield of ~400mg/L. Two EPS fractions (namely a soluble and an insoluble fraction) were isolated by ethanol precipitation and the soluble 'ropy' fraction was further purified to achieve ~98% purity. The elemental analysis of the purified fraction revealed the presence of nitrogen (~2.7% w/w). This could be due to the interaction of some peptides (from the growth medium) with the EPS. The polysaccharide composition of the soluble EPS fraction comprised of galactose, glucose, rhamnose and mannose residues (5:1:0.6:0.5). Traces of glucosamine were also found in the fraction. The purified fraction of 2483 EPS was characterised. Using a capillary viscometer, an intrinsic viscosity of ~2013mL/g was determined. The flow curves of the 2483 EPS solutions obtained using a rotational viscometer showed shear-thinning behaviour and an exponent value of ~0.76 (based on the Cross-type model) is typical of random coil polymers. The concentration dependence of the viscosity plot produced gradients of ~1.1 in the dilute domain and ~3.3 in the semi-dilute to concentrated domain. The coil overlap parameters at three concentration domains (c*[ŋ],ccr[ŋ] and c**[ŋ]) were 0.55, 2.86 and 5.67 respectively. The molecular parameters of the 2483 EPS were found via static light scattering measurements to have a weight-average molar mass (Mw.) of ~2 x 106 Da, a z-average root-mean-square radius ((r2g)z1/2) of ~165nm and a low polydispersity index (Mw/Mn ~1.15). The plot of Mw versus (r2g)z1/2 gave a gradient of approximately 0.5, which also suggested that the EPS polymer adopted a random coil conformation. The second part of the research involved gellan gum. Two gellan samples were studied. The first gellan sample was obtained from the fermentation of Sphingomonas elodea ATCC 31461 using milk permeate-based medium (31461). The second sample was a commercial high acyl gellan (LT100). Both gellan samples were converted to their sodium forms (Na-31461 and Na-LT100 gellan) using cation exchange resin and purified. The Na-gellan samples were highly sensitive to changes in Na+ concentrations. From oscillatory measurements, it was found that the complex moduli of the two Na-gellan samples superimposed closely at a specific Na+ concentration. The model for the conformational changes of Na-gellan molecules from a solution to a gel was proposed based on rheological and light scattering data. At very low Na+ concentrations (<19mM, in the case of Na-LT100). Na-gellan molecules were single-stranded (Mw ~2.5 x 10 5 Da) and adopted random coil conformation (exponent value based on the Cross-type model of ~0.76). At a slightly higher Na+ concentration (~19-24mM), Na-gellan molecules formed double-helices which led to a two-fold increase in molecular weight (M w ~5.2 x 105 Da). The double-stranded molecule appeared to be stiffer (exponent value of the Cross-type model ~0.82) and the mechanical spectra (G',G”) demonstrated 'weak ge' characteristics. A further increase in the Na+ concentration (>24mM) resulted in the formation of a gel network. The study also found that at low Na+concentration, both single-stranded and double-stranded Na-gellan molecules had a tendency to form aggregates under zero-shear conditions. The interactions involved in these aggregates were considered weak and transient, according to the Cox-Merz plot and light scattering data.

Made available in DSpace on 2016-06-07T17:12:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-12-12. Added 1 bitstream(s) on 2016-06-07T17:17:18Z : No. of bitstreams: 1 000864718.pdf: 1816225 bytes, checksum: 9e4f9a17fbf8157743324634958c467a (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O presente estudo foi dividido em duas etapas, a primeira propôs a produção de enzimas lignocelulósicas por linhagens do gênero Trichoderma por fermentação em estado sólido sob diferentes condições físico-químicas. Após seleção inicial, quatro dentre dez linhagens analisadas, apresentaram resultados satisfatórios quanto à atividade enzimática. Dentre as quatro, foram identificadas as espécies T. virens, T. harzianum e T. aspereloides. A maior atividade de CMCase (23 U/g), foi obtida do cultivo de T. asperelloides e a maior atividade de β-glicosidase (4 U/g) e xilanase (1640 U/g) do cultivo de T. virens. Na segunda etapa deste estudo, foi avaliada a eficiência do pré-tratamento com e sem o uso de micro-ondas associado a soluções de ácido fosfórico (0,05 M), hidróxido de sódio (0,01 M), glicerol (10%) e água no tratamento do bagaço de cana. Dos tratamentos ao qual o bagaço foi submetido, o que resultou em maior liberação de compostos fenólicos totais (4,24 mg/g) e açúcares redutores (0,06 ± 0 mg/g), foram os tratamentos por micro-ondas associados ao NaOH e glicerol, respectivamente. Os resultados de perda de massa após o tratamento foram significativos no tratamento com micro-ondas e NaOH (14%). O bagaço de cana pré-tratado foi incubado com o preparo enzimático de Trichoderma virens, T. asperelloides, T. harzianum ou a enzima comercial Celluclast. Após 24 horas de incubação foram liberados 535 mg/g de açúcar redutor na hidrólise da espécie T. virens. As análises termogravimétricas e morfológicas do bagaço de cana tratado com micro-ondas e NaOH, apontaram mudanças na estrutura do material evidenciando a eficiência do tratamento na desestruturação da biomassa / This study was divided in two steps, the first investigated the production of lignocelullosic enzymes for specimens of Trichoderma cultivated by state solid fermentation under different conditions physical-chemical. For ten specimens available, four showed satisfactory results of enzymatic production, being identified three species. T. virens, T. harzianum e T. aspereloides). The greatest production of CMCase (23 U/g), was obtained by T. asperelloides and the greatest production of β-glicosidase (4U/g) and xilanase (1640U/g) were obtained by T. virens. In the second investigation, was tested the efficiency of pre-treatment of bagasse sugar cane with microwave radiation in presence of acid phosphoric (0.05M), sodium hydroxide (0.01M), glycerol (10%) all diluted in water in fiber structure. About the treatments of the bagasse, the most efficient in the liberation of phenolic compounds (4.24 mg/g) and reducing sugars (0.06±0 mg/g) was the solution in microwave with NaOH and glycerol, respectively. The dry weight results after the treatment were significant, with a maximum of 14% loss of the initial in treatment with NaOH. The thermogravimetry and morphological analysis of treated bagasse with a microwave and NaOH, showed changes in the structure of the material showing the effectiveness of treatment in biomass breakdown

Neste trabalho, são descritos os detalhes da montagem de um sistema de cultivo microbiano em estado sólido, cujo elemento principal é um biorreator de tambor rotativo em escala de bancada, com casco em vidro refratário com aproximadamente 6,2 litros de volume. A montagem do equipamento exigiu estudos para a definição dos seguintes aspectos: geometria do reator; controle de frequência e período de agitação; umidificação, aquecimento e controle do fluxo do ar injetado no sistema; mistura do meio de cultivo; medição e controle da temperatura do meio; retirada de amostras. O sistema desenvolvido foi avaliado, tendo como processo fermentativo modelo o cultivo de Aspergillus niger T0005/007-2, microrganismo produtor de enzimas pectinolíticas. Os testes foram feitos em um meio contendo farelo de trigo como suporte sólido, avaliando-se a influência de três parâmetros principais agitação, massa de meio de cultivo e temperatura do meio sobre o crescimento celular e a produção de endo-poligalacturonase (PG) por A. niger. Três formas de agitação do meio sólido foram comparadas: sem agitação; agitação a 1 rpm por 5 minutos a cada duas horas; agitação a 1 rpm por 1 hora e 55 minutos a cada duas horas. A segunda forma de agitação levou ao melhor crescimento celular, 81 mg.g-1, e a atividade de endo-PG da ordem de 80 U.g-1, semelhante ao estimado com o sistema estático. Com a terceira forma de agitação, aparentemente houve dano ao micélio fúngico e, com isso, resultados inferiores foram alcançados. A avaliação do efeito da massa de meio de cultivo sobre o processo foi feita com cargas crescentes de meio que resultaram na ocupação de 30, 45 e 60 % do volume útil do reator. Quanto ao crescimento celular, o melhor resultado foi alcançado com a menor carga de meio, enquanto que a carga intermediária resultou no mais alto título enzimático final, 107,2 U.g-1. Nos experimentos sobre a influência da temperatura sobre o cultivo de A. niger, a maior atividade enzimática (80,6 U.g-1) foi obtida numa condição de trabalho que permitiu que a temperatura do meio atingisse valores da ordem de 45ºC. Com o meio mantido a 30ºC, a atividade enzimática máxima foi substancialmente mais baixa, 46,4 U.g-1. Nos testes realizados com o processo modelo, não se verificou uma clara influência positiva da agitação sobre a produção de endo-PG. Entretanto, a partir dos experimentos com temperatura controlada, é possível sugerir que a formação de endo-PG é favorecida por uma condição de estresse para o microrganismo, no caso representado por temperaturas do meio acima de 40ºC, visto que a temperatura ideal de crescimento de A. niger encontra-se na faixa de 28 a 34ºC. Este resultado, que discorda do que é genericamente descrito na literatura especializada sobre cultivos em estado sólido, é um exemplo da importância de dispor-se de um biorreator de tambor rotativo de pequena escala como equipamento básico para a realização de estudos fundamentais a respeito deste tipo de processo. Adicionalmente, o fato de o corpo do reator ser construído em vidro permite a visualização do espaço interno do tambor rotativo e observar o efeito da agitação sobre o meio de cultivo. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-02T17:41:21Z No. of bitstreams: 1 Dissertacao Tomas Augusto Polidoro.pdf: 1493269 bytes, checksum: 0ed8a1384e54fe0a00f47be237707cbf (MD5) / Made available in DSpace on 2014-06-02T17:41:21Z (GMT). No. of bitstreams: 1 Dissertacao Tomas Augusto Polidoro.pdf: 1493269 bytes, checksum: 0ed8a1384e54fe0a00f47be237707cbf (MD5) / In this work, details on the assembling of a solid state cultivation system, whose main component is a bench scale rotating-drum bioreactor, are described. The bioreactor was built in refractory glass and has an approximate volume of 6.2 liters. To assemble the equipment, the following aspects have been studied: geometry of the bioreactor; control of frequency and period of agitation; moistening, warming and controlling of the inlet air flux; mixing of cultivation medium; determination and control of medium temperature; sample withdrawn. The developed system was evaluated, being the cultivation of the pectinolytic enzymeproducing microorganism Aspergillus niger T0005/007-2 used as the model process. The fermentative tests were carried out in a medium containing wheat-straw as solid support and were used to evaluate the effects of three main parameters agitation, mass of cultivation medium and medium temperature on the cell growth and the production of endopolygalacturonase (endo-PG) by A. niger. For agitation of the solid medium, three modes were compared: no agitation; agitation of 1 rpm for 5 minutes each 2 hours; agitation for 1 hour and 55 minutes, each 2 hours. The second mode of agitation led to the best cell growth, 81 mg.g-1, and to endo-PG activity of approximately 80 U.g-1, similar to that obtained with the static system. With the third mode of agitation occurred, apparently, some damage to fungus mycelium and inferior results were achieved. The evaluation of the mass of cultivation medium on the process was done by loading the reactor with masses that result in the occupation of 30, 45 and 60% of the working volume of the bioreactor. With respect to the cell growth, the best result was attained with the smallest load of medium, whereas the intermediate load resulted in the highest endo-PG activity, 107.2 U.g-1. In the experiments on the influence of the temperature on the cultivation of A. niger, the largest endo-PG activity (80.6 U.g-1) was obtained in a process condition that allowed that the temperature reached values close to 45ºC. When the medium temperature was controlled at 30ºC, the endo-PG activity was substantially lower, 46.4 U.g-1. In the tests with the model process, no clearly positive influence of agitation on the production of endo-PG was observed. From the temperature-controlled experiments however, it is possible to suggest that endo-PG formation is favored by a stress condition for the microorganism, represented in this case by medium temperatures over 40ºC, since the optimal temperatures for A. niger growth is found in the range of 28 to 34ºC. This result disagrees from what is generically described in the specialized literature for the solid state cultivations, being this fact an example of the importance of having a small-scale rotating-drum bioreactor as a basic equipment for fundamental studies on that type of fermentative process. Additionally, the fact of the reactor body being built on glass allows the inspection of the internal space of the rotating drum and to observe the effects of agitation on the cultivation medium.

Este trabalho apresenta um estudo de caso para aplicação do sistema de Análise de Perigos e Pontos Críticos de Controle no setor vitivinícola, levando em conta as várias etapas de elaboração presentes no processo, bem como todos os cuidados e avaliações necessárias. Trata-se de um método que prevê uma avaliação técnica de produtos. Seu objetivo, em relação ao vinho, é detectar possíveis pontos de contaminação e controlá-los, levando-se em conta todos os agentes envolvidos nesse procedimento. Por isso sua implementação segue regras baseadas em pesquisas. Seguir em detalhes seus fundamentos garante uma implantação eficaz do sistema. Tais diretrizes seguem normas regulamentadas, já trabalhadas e aceitas nacional e internacionalmente. O resultado de tal sistematização é um produto com mais qualidade, com uma segurança alimentar aceita pelo consumidor. Isso gera aumento da lucratividade, fidelização de consumidores em relação à marca e inserção permanente da empresa, no campo dos vinhos aceitos e apreciados dentro de uma procedência válida e com certificação de segurança. No caso do estudo exposto fez-se uma sistematização geral da Análise de Perigos e Pontos Críticos de Controle para uso nas vinícolas onde foram levadas em conta as etapas de elaboração do vinho desde a colheita e transporte das uvas até a estocagem do produto final. Após a realização da Análise de Perigos e Pontos Críticos de Controle geral foi escolhida a Vinícola Larentis situada no Vale dos Vinhedos, Estado do Rio Grande do Sul – Brasil. A primeira etapa, realizada na Vinícola, foi a determinação do grau de atendimento ao programa de pré- requisitos preconizados pelo sistema de Análise de Perigos e Pontos Críticos de Controle. Na segunda etapa foi elaborado o plano de Análise de Perigos e Pontos Críticos de Controle para o processo de vinificação do vinho Merlot. A análise de perigos na vinícola foi dividida em setores, onde observou-se perigos que podem ocorrer em quase todos os setores da vinícola e no final foram propostas ações corretivas dos pontos críticos de controle. Desta forma, o uso do sistema Análise de Perigos e Pontos Críticos de Controle foi pensado e discutido, pois ele minimiza os perigos do processo de vinificação, reduz custos de produção e melhora a qualidade do produto final. / Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2014-08-25T18:08:17Z No. of bitstreams: 1 Dissertacao Bruno Zorrer Larentis.pdf: 1214667 bytes, checksum: b71c1817c10d1139f8ac921907021c2d (MD5) / Made available in DSpace on 2014-08-25T18:08:18Z (GMT). No. of bitstreams: 1 Dissertacao Bruno Zorrer Larentis.pdf: 1214667 bytes, checksum: b71c1817c10d1139f8ac921907021c2d (MD5) / This paper presents a case study for the use of a Hazard and Critical Control Points System (HACCP) in the wine industry, considering all elaboration stages as well as cares and necessary evaluations. HACCP is a method that provides technical evaluation of products and regarding to winemaking, it aims to detect possible contamination points and their control, taking into account all agents involved on the elaboration process. Therefore its implementation follows rules based upon documented research. Tracing the system foundations in details ensures its effective application. These guidelines follow regulated rules, already used and accepted worldwide. The outcome of such systematization is a higher quality product, with food safety accepted by the consumer. This generates increased profitability, loyalty towards the brand and places the company within the market of wines accepted and appreciated for their valid provenance and safety certification. On this study it was made a general systematization of the HACCP for wineries, taking into account all stages of winemaking, from harvesting and transporting the grapes up to the final product storage. After the general analysis, Vinícola Larentis, placed on Vale dos Vinhedos, State of Rio Grande do Sul, Brazil, was chosen to carry out the investigation. The first step was accomplished in the winery, determining the compliance degree with the prerequisites envisaged by the HACCP. The second step was to plan the system for Merlot wine vinification. With the analysis divided into areas, it was observed that hazards may occur in almost all of them and eventually, corrective actions were proposed. Therefore, the HACCP was considered and discussed, as it lessens the hazards of the winemaking process, decreases production costs and consequently improves the final product quality.

Orientador: Eleni Gomes / Banca: João Claudio Thomeo / Banca: Mauricio Boscolo / Banca: Sandra Helena da Cruz / Banca: Sarita Cândida Rabelo / Resumo: O presente estudo foi dividido em duas etapas, a primeira propôs a produção de enzimas lignocelulósicas por linhagens do gênero Trichoderma por fermentação em estado sólido sob diferentes condições físico-químicas. Após seleção inicial, quatro dentre dez linhagens analisadas, apresentaram resultados satisfatórios quanto à atividade enzimática. Dentre as quatro, foram identificadas as espécies T. virens, T. harzianum e T. aspereloides. A maior atividade de CMCase (23 U/g), foi obtida do cultivo de T. asperelloides e a maior atividade de β-glicosidase (4 U/g) e xilanase (1640 U/g) do cultivo de T. virens. Na segunda etapa deste estudo, foi avaliada a eficiência do pré-tratamento com e sem o uso de micro-ondas associado a soluções de ácido fosfórico (0,05 M), hidróxido de sódio (0,01 M), glicerol (10%) e água no tratamento do bagaço de cana. Dos tratamentos ao qual o bagaço foi submetido, o que resultou em maior liberação de compostos fenólicos totais (4,24 mg/g) e açúcares redutores (0,06 ± 0 mg/g), foram os tratamentos por micro-ondas associados ao NaOH e glicerol, respectivamente. Os resultados de perda de massa após o tratamento foram significativos no tratamento com micro-ondas e NaOH (14%). O bagaço de cana pré-tratado foi incubado com o preparo enzimático de Trichoderma virens, T. asperelloides, T. harzianum ou a enzima comercial Celluclast. Após 24 horas de incubação foram liberados 535 mg/g de açúcar redutor na hidrólise da espécie T. virens. As análises termogravimétricas e morfológicas do bagaço de cana tratado com micro-ondas e NaOH, apontaram mudanças na estrutura do material evidenciando a eficiência do tratamento na desestruturação da biomassa / Abstract: This study was divided in two steps, the first investigated the production of lignocelullosic enzymes for specimens of Trichoderma cultivated by state solid fermentation under different conditions physical-chemical. For ten specimens available, four showed satisfactory results of enzymatic production, being identified three species. T. virens, T. harzianum e T. aspereloides). The greatest production of CMCase (23 U/g), was obtained by T. asperelloides and the greatest production of β-glicosidase (4U/g) and xilanase (1640U/g) were obtained by T. virens. In the second investigation, was tested the efficiency of pre-treatment of bagasse sugar cane with microwave radiation in presence of acid phosphoric (0.05M), sodium hydroxide (0.01M), glycerol (10%) all diluted in water in fiber structure. About the treatments of the bagasse, the most efficient in the liberation of phenolic compounds (4.24 mg/g) and reducing sugars (0.06±0 mg/g) was the solution in microwave with NaOH and glycerol, respectively. The dry weight results after the treatment were significant, with a maximum of 14% loss of the initial in treatment with NaOH. The thermogravimetry and morphological analysis of treated bagasse with a microwave and NaOH, showed changes in the structure of the material showing the effectiveness of treatment in biomass breakdown / Doutor

Neste trabalho, são descritos os detalhes da montagem de um sistema de cultivo microbiano em estado sólido, cujo elemento principal é um biorreator de tambor rotativo em escala de bancada, com casco em vidro refratário com aproximadamente 6,2 litros de volume. A montagem do equipamento exigiu estudos para a definição dos seguintes aspectos: geometria do reator; controle de frequência e período de agitação; umidificação, aquecimento e controle do fluxo do ar injetado no sistema; mistura do meio de cultivo; medição e controle da temperatura do meio; retirada de amostras. O sistema desenvolvido foi avaliado, tendo como processo fermentativo modelo o cultivo de Aspergillus niger T0005/007-2, microrganismo produtor de enzimas pectinolíticas. Os testes foram feitos em um meio contendo farelo de trigo como suporte sólido, avaliando-se a influência de três parâmetros principais agitação, massa de meio de cultivo e temperatura do meio sobre o crescimento celular e a produção de endo-poligalacturonase (PG) por A. niger. Três formas de agitação do meio sólido foram comparadas: sem agitação; agitação a 1 rpm por 5 minutos a cada duas horas; agitação a 1 rpm por 1 hora e 55 minutos a cada duas horas. A segunda forma de agitação levou ao melhor crescimento celular, 81 mg.g-1, e a atividade de endo-PG da ordem de 80 U.g-1, semelhante ao estimado com o sistema estático. Com a terceira forma de agitação, aparentemente houve dano ao micélio fúngico e, com isso, resultados inferiores foram alcançados. A avaliação do efeito da massa de meio de cultivo sobre o processo foi feita com cargas crescentes de meio que resultaram na ocupação de 30, 45 e 60 % do volume útil do reator. Quanto ao crescimento celular, o melhor resultado foi alcançado com a menor carga de meio, enquanto que a carga intermediária resultou no mais alto título enzimático final, 107,2 U.g-1. Nos experimentos sobre a influência da temperatura sobre o cultivo de A. niger, a maior atividade enzimática (80,6 U.g-1) foi obtida numa condição de trabalho que permitiu que a temperatura do meio atingisse valores da ordem de 45ºC. Com o meio mantido a 30ºC, a atividade enzimática máxima foi substancialmente mais baixa, 46,4 U.g-1. Nos testes realizados com o processo modelo, não se verificou uma clara influência positiva da agitação sobre a produção de endo-PG. Entretanto, a partir dos experimentos com temperatura controlada, é possível sugerir que a formação de endo-PG é favorecida por uma condição de estresse para o microrganismo, no caso representado por temperaturas do meio acima de 40ºC, visto que a temperatura ideal de crescimento de A. niger encontra-se na faixa de 28 a 34ºC. Este resultado, que discorda do que é genericamente descrito na literatura especializada sobre cultivos em estado sólido, é um exemplo da importância de dispor-se de um biorreator de tambor rotativo de pequena escala como equipamento básico para a realização de estudos fundamentais a respeito deste tipo de processo. Adicionalmente, o fato de o corpo do reator ser construído em vidro permite a visualização do espaço interno do tambor rotativo e observar o efeito da agitação sobre o meio de cultivo. / In this work, details on the assembling of a solid state cultivation system, whose main component is a bench scale rotating-drum bioreactor, are described. The bioreactor was built in refractory glass and has an approximate volume of 6.2 liters. To assemble the equipment, the following aspects have been studied: geometry of the bioreactor; control of frequency and period of agitation; moistening, warming and controlling of the inlet air flux; mixing of cultivation medium; determination and control of medium temperature; sample withdrawn. The developed system was evaluated, being the cultivation of the pectinolytic enzymeproducing microorganism Aspergillus niger T0005/007-2 used as the model process. The fermentative tests were carried out in a medium containing wheat-straw as solid support and were used to evaluate the effects of three main parameters agitation, mass of cultivation medium and medium temperature on the cell growth and the production of endopolygalacturonase (endo-PG) by A. niger. For agitation of the solid medium, three modes were compared: no agitation; agitation of 1 rpm for 5 minutes each 2 hours; agitation for 1 hour and 55 minutes, each 2 hours. The second mode of agitation led to the best cell growth, 81 mg.g-1, and to endo-PG activity of approximately 80 U.g-1, similar to that obtained with the static system. With the third mode of agitation occurred, apparently, some damage to fungus mycelium and inferior results were achieved. The evaluation of the mass of cultivation medium on the process was done by loading the reactor with masses that result in the occupation of 30, 45 and 60% of the working volume of the bioreactor. With respect to the cell growth, the best result was attained with the smallest load of medium, whereas the intermediate load resulted in the highest endo-PG activity, 107.2 U.g-1. In the experiments on the influence of the temperature on the cultivation of A. niger, the largest endo-PG activity (80.6 U.g-1) was obtained in a process condition that allowed that the temperature reached values close to 45ºC. When the medium temperature was controlled at 30ºC, the endo-PG activity was substantially lower, 46.4 U.g-1. In the tests with the model process, no clearly positive influence of agitation on the production of endo-PG was observed. From the temperature-controlled experiments however, it is possible to suggest that endo-PG formation is favored by a stress condition for the microorganism, represented in this case by medium temperatures over 40ºC, since the optimal temperatures for A. niger growth is found in the range of 28 to 34ºC. This result disagrees from what is generically described in the specialized literature for the solid state cultivations, being this fact an example of the importance of having a small-scale rotating-drum bioreactor as a basic equipment for fundamental studies on that type of fermentative process. Additionally, the fact of the reactor body being built on glass allows the inspection of the internal space of the rotating drum and to observe the effects of agitation on the cultivation medium.

Este trabalho apresenta um estudo de caso para aplicação do sistema de Análise de Perigos e Pontos Críticos de Controle no setor vitivinícola, levando em conta as várias etapas de elaboração presentes no processo, bem como todos os cuidados e avaliações necessárias. Trata-se de um método que prevê uma avaliação técnica de produtos. Seu objetivo, em relação ao vinho, é detectar possíveis pontos de contaminação e controlá-los, levando-se em conta todos os agentes envolvidos nesse procedimento. Por isso sua implementação segue regras baseadas em pesquisas. Seguir em detalhes seus fundamentos garante uma implantação eficaz do sistema. Tais diretrizes seguem normas regulamentadas, já trabalhadas e aceitas nacional e internacionalmente. O resultado de tal sistematização é um produto com mais qualidade, com uma segurança alimentar aceita pelo consumidor. Isso gera aumento da lucratividade, fidelização de consumidores em relação à marca e inserção permanente da empresa, no campo dos vinhos aceitos e apreciados dentro de uma procedência válida e com certificação de segurança. No caso do estudo exposto fez-se uma sistematização geral da Análise de Perigos e Pontos Críticos de Controle para uso nas vinícolas onde foram levadas em conta as etapas de elaboração do vinho desde a colheita e transporte das uvas até a estocagem do produto final. Após a realização da Análise de Perigos e Pontos Críticos de Controle geral foi escolhida a Vinícola Larentis situada no Vale dos Vinhedos, Estado do Rio Grande do Sul – Brasil. A primeira etapa, realizada na Vinícola, foi a determinação do grau de atendimento ao programa de pré- requisitos preconizados pelo sistema de Análise de Perigos e Pontos Críticos de Controle. Na segunda etapa foi elaborado o plano de Análise de Perigos e Pontos Críticos de Controle para o processo de vinificação do vinho Merlot. A análise de perigos na vinícola foi dividida em setores, onde observou-se perigos que podem ocorrer em quase todos os setores da vinícola e no final foram propostas ações corretivas dos pontos críticos de controle. Desta forma, o uso do sistema Análise de Perigos e Pontos Críticos de Controle foi pensado e discutido, pois ele minimiza os perigos do processo de vinificação, reduz custos de produção e melhora a qualidade do produto final. / This paper presents a case study for the use of a Hazard and Critical Control Points System (HACCP) in the wine industry, considering all elaboration stages as well as cares and necessary evaluations. HACCP is a method that provides technical evaluation of products and regarding to winemaking, it aims to detect possible contamination points and their control, taking into account all agents involved on the elaboration process. Therefore its implementation follows rules based upon documented research. Tracing the system foundations in details ensures its effective application. These guidelines follow regulated rules, already used and accepted worldwide. The outcome of such systematization is a higher quality product, with food safety accepted by the consumer. This generates increased profitability, loyalty towards the brand and places the company within the market of wines accepted and appreciated for their valid provenance and safety certification. On this study it was made a general systematization of the HACCP for wineries, taking into account all stages of winemaking, from harvesting and transporting the grapes up to the final product storage. After the general analysis, Vinícola Larentis, placed on Vale dos Vinhedos, State of Rio Grande do Sul, Brazil, was chosen to carry out the investigation. The first step was accomplished in the winery, determining the compliance degree with the prerequisites envisaged by the HACCP. The second step was to plan the system for Merlot wine vinification. With the analysis divided into areas, it was observed that hazards may occur in almost all of them and eventually, corrective actions were proposed. Therefore, the HACCP was considered and discussed, as it lessens the hazards of the winemaking process, decreases production costs and consequently improves the final product quality.

Submitted by Biblioteca Central (biblioteca@unicap.br) on 2017-12-13T18:19:23Z No. of bitstreams: 1 dissertacao_daniel_paulo_oliveira.pdf: 38291048 bytes, checksum: cb2f1b941a2d83e08674ae871266ad51 (MD5) / Made available in DSpace on 2017-12-13T18:19:23Z (GMT). No. of bitstreams: 1 dissertacao_daniel_paulo_oliveira.pdf: 38291048 bytes, checksum: cb2f1b941a2d83e08674ae871266ad51 (MD5) Previous issue date: 2007-08-08 / The enzymatic biotechnology industry is growing up progressively in the last decades with the utilization e production of diverse microbial enzymes. Amylases are enzymes which hydrolyze starch molecules to give diverse products including dextrin's and progressively glucose units. They play a wide field of applications. In food industries, in beer industry and others fermented drinks, in cereal for baby's food and animal feed, in paper and cellulose industry, textile industry, in detergent and cleaning products industry, in chemical and pharmaceutical industry. Screening was carrying out in solid media to amylase production in 5 strains isolated from contaminated ambient by petroleum in different temperatures (28 °C and 37 °C), respectively. The results obtained evidenced that the isolated Bacillus licheniformis UCP 1009 showed the halo formation characteristically of the 55 mm to amylase, after 72 hours of incubation. After the selection of the microorganism, fermentations was carrying out to amylase production, replacing the soluble starch, by corn starch and potato starch, trough of factorial planning 23 with 4 central's points, having a amylase's production as a answering variable, during 96 hours. The microbial growth profile was established, the pH, the glucose consumption by the DNS and determination of specific enzyme activity. The results obtained evidenced that the corn starch shown an specific activity of 0.756 U/mg, at a pH of 8.82 and a enzymatic activity of amylase 0.99 U/dL, showing a industrial potential. / A indústria biotecnológica enzimática vem aumentando progressivamente nas últimas décadas com a utilização e produção de diversas enzimas microbianas. As amilases são enzimas que hidrolisam moléculas de amido liberando diversos produtos secundários, incluindo as dextrinas e progressivamente por unidades de glicose. Apresentam um amplo campo de aplicações na indústria de alimentos, em cervejarias e bebidas fermentadas, em cereais para alimentação infantil e ração animal, indústrias de papel e celulose, têxtil, de detergentes, química, farmacêutica e produtos de limpeza. Foram realizados ensaios de seleção em meio sólido para produção de amilase por 05 isolados de ambientes contaminados por petróleo em diferentes temperaturas (28 e 37 °C), respectivamente. Os resultados obtidos evidenciaram que o isolado Bacillus licheniformis UCP 1009 apresentou a formação de halo característico de 55 mm para amilase, após 72 horas de incubação. Após a seleção do microrganismo, foram realizados fermentações para produção de amilase, substituindo o amido solúvel, pelo amido de milho e de batata, através de um planejamento fatorial 23 com quatro pontos centrais, tendo a variável de resposta a produção de amilase, durante 96 horas. Foram estabelecidos o perfil de crescimento microbiano, o pH, o consumo de glicose pelo método do DNS e a determinação da atividade específica da enzima. Os resultados obtidos evidenciaram que o amido de milho apresentou uma atividade específica de 0,756 U/mg, a um pH de 8,82 e uma atividade enzimática da amilase de 0,99 U/dL, demonstrando um potencial industrial.

The current trend of increasing demand for minimally processed food requires more effective preservation technologies than are presently used. In this study, an investigation has been made into a novel strategy to control some common foodborne pathogens, and therefore, to provide an alternative means for enhancing the safety and extending the shelf lives of food products. Modified atmosphere is able to extend the shelf life of seafood and meat products. In this study, a simulated controlled atmosphere (CA) broth system was used to investigate the potential of a modified atmosphere rich in CO2 at a concentration of 40%, supplemented with N2, to control common foodborne pathogens, such as Listeria monocytogenes, Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, Staphylococcus aureus and Vibrio parahaemolyticus. Controlled atmosphere significantly reduced the exponential growth rates of all tested pathogens, while the effects on other growth parameters (eg. lag phase duration and maximum population density) depended on the individual species and the specific growth conditions. The CA significantly extended the lag phase durations of S. aureus and V. parahaemolyticus at 20 degrees C at both pH 6.3 and 6.8, and that of L. monocytogenes at both 7 degrees C and 20 degrees C, and at both pH 6.3 and 6.8. The CA also significantly lowered the maximum population densities of S. aureus and V. parahaemolyticus at 20 degrees C, at pH 6.3 and 6.8, S. Typhimurium at pH 6.8, and L. monocytogenes at pH 6.3 and 7 degrees C. E. coli O157:H7 and S. Typhimurium were more resistant to the inhibitory effect of the CA, while S. aureus and V. parahaemolyticus were most sensitive. The inhibitory effect of CA was due mainly to the extensions of the lag phase duration and the reduction of the exponential growth rates of the test pathogens. This study confirms other studies that CA as a means for food preservation provides potential to control foodborne pathogens and therefore enhance the safety of a food product. The use of lactic acid bacteria (LAB) in controlling spoilage microorganisms and pathogens in foods has been a popular research theme worldwide. In this study, the antimicrobial effects of 18 lactic acid bacteria strains were evaluated in vitro, with emphasis on the most effective strain, the newly characterised Lactobacillus reuteri DPC16. The results demonstrated antagonistic effects of many strains against L. monocytogenes, E. coli O157:H7, S. Typhimurium and S. aureus. L. reuteri DPC16 showed the strongest antimicrobial activity against the tested pathogens including both Gram-positive and Gram-negative bacteria. Co-cultivation of L. reuteri DPC16, and co-incubation of its spent culture supernatant (DPC16-SCS), with the pathogens have demonstrated that the antimicrobial effect is bactericidal and valid at pH 4 - 6.5 and at a temperature as low as 10 degrees C. Further characterisation of the antimicrobial effect of L. reuteri DPC16 showed it to be mainly due to the presence of reuterin (ß-hydroxypropionaldehyde), although lactic acid may have also played a role. These characteristics of L. reuteri DPC16 and its metabolite reuterin make it an unique and potent candidate as a biopreservative to control both Gram-positive and Gram-negative bacteria in foods. The combination of L. reuteri DPC16 and CA was assessed for its inhibitory effect on L. monocytogenes using DPC16-SCS and the fermentative supernatant of L. reuteri DPC16 from a glycerol-water solution (DPC16-GFS). The results showed that both of these supernatants, at 25 AU/mL, in combination with CA (60% CO2:40% N2) had a combined inhibitory effect on L. monocytogenes which could not be achieved by any one of the individual factors alone. Analysis of the levels of expression of some stress response genes of L. monocytogenes, after growth in the presence of L. reuteri DPC16 supernatant and/or CA, showed that the expression of some genes was affected including genes betL, gbuA and opuCA responsible for osmosis adaptation and genes gadA, gadB and gadC responsible for acid tolerance. Induction of gbuA, gadB and gadC by the culture supernatant suggests activation of osmotic and acid adaptation and that these genes play a major role in the culture supernatant-induced stresses. An investigation was also carried out to determine if the changes in gene expression conferred a cross-protection to heat. The result showed that the survival of L. monocytogenes grown in the presence of the culture supernatant and CA was significantly increased after exposure to heat treatment at 56oC, suggesting that a cross-protection to thermal stress had been induced. Based on these findings it is proposed that a comprehensive novel strategy incorporating both L. reuteri DPC16 or its fermentative products and a modified atmosphere rich in CO2 could be developed to potentially control foodborne pathogens in food products.

The objective of this study was to investigate the effects of preheat treatments on fouling by fresh whole milk (FWM), recombined whole milk (RCB) and reconstituted whole milk (Recon) in the high-temperature heater of indirect UHT plants. Various preheat treatments prior to evaporation during milk powder manufacture were applied to skim milk powder (SMP, 75 °C 2 s, 85 °C, 155 s and 95 °C, 155 s) and whole milk powder (WMP, 95 °C, 33 s). These preheat treatments were so-called “evaporator preheat treatments”. Skim milk powder (SMP) and whole milk powder (WMP) were derived from the same original batch of pasteurised FWM to remove the effects of the variation in milk composition between different milk batches. These SMPs were recombined with anhydrous milk fat and water to prepare RCB, and WMPs were reconstituted with water to prepare Recon. Then, (homogenized) FWM, RCB and Recon were subjected to various preheat treatments (75 °C, 11 s, 85 °C, 147 s and 95 °C, 147 s) prior to UHT processing. These preheat treatments were so-called “UHT preheat treatments”. Temperature difference (hot water inlet temperature – milk outlet temperature) was taken as a measure of the extent of fouling in the high-temperature heater. The slope of the linear regression of temperature difference versus time (for two hours of UHT processing) was taken as fouling rate (°C/h). Increasing both evaporator and UHT preheat treatments resulted in increasing fouling rate and total deposit weight for all three whole milk types for several milk batches. In the case of FWM, there was no reduction in fouling rate with increasing UHT preheat treatment whether FWM was homogenized then preheated, preheated then homogenized or not homogenized at all. These findings, which are wholly consistent and well replicated, are in apparent conflict with the results of most previous comparable studies. Possible reasons for this are explained. Further investigations of the effects of homogenization relating to the role of whey protein on the surface of the fat globules showed that whey protein associated with the membrane covering the surface of fat globules for homogenized then preheated FWM, RCB and Recon and that association increased with increasing heating process stage. The increasing association of whey protein with the milk fat globules membrane with increasing severity of heating process stage became faster when preheat treatment was more severe: the association of whey protein plateaued on intermediate temperature heating when the milks were preheated at 75°C, 11 s and on preheating when the milks were preheated at 95°C, 147 s. In the case of FWM, the thickness of the membrane covering the surface of fat globules for homogenized then preheated FWM, which increased with the severity of heating process stage, was greater than the thickness of the membrane in preheated then homogenized FWM. Preheating then homogenization resulted in the greater interfacial spreading of small molecules on the surface of fat globules, i.e. whey protein or small molecules from the disintegration of casein micelles during preheating. Possible basic mechanisms for UHT fouling in the high-temperature heater include: the reduction in the solubility of calcium phosphate and the deposition of protein as fat-bound protein and non-fat-bound protein. When non-fat-bound protein in milk plasma deposited, it could be a carrier for the deposition of mineral, such as, the precipitate of calcium phosphate in the casein micelles or the deposition of complexes between whey protein and casein micelles.